This invention relates generally to an internal combustion engine and more specifically to prepackaged piston assemblies which are provided with a plurality of piston rings positioned on each piston member and held in a compressed position.
Internal combustion engines have numerous components which need to be assembled in order to provide a complete engine. Engine repair facilities, new engine manufacturers and engine re-manufactures are constantly looking for ways to improve quality and reduce cost of assembling engines. Many engine components are supplied by manufactures other than the engine assembly facility. Engine components such as, pistons, rings, connecting rods and wrist pins are often packaged, shipped and stored separately at the engine manufacturer or assembler. Supplying engine components in this manner is costly, and increases the opportunity to damage components.
Additionally, when used engine components have undergone an excessive amount of wear, the performance and efficiency of the engine is reduced. Engines which have undergone excessive wear are often rebuilt by replacing major components. Many of the components that are normally replaced during the rebuilding process include pistons, piston rings, connecting rods, rod bearings, and main bearings. This rebuilding of the engine brings the engine back to, or near, the engine manufacturer""s original performance or specifications. To insure the quality of the rebuilt engine the rebuild process is preferably done in a controlled environment such as a factory or repair shop.
Often with large machines utilizing internal combustion engines, such as those used in the construction and mining industry, the size of the machine restricts transportation to an engine rebuild shop, or the time permitted for the rebuild process requires that the engine of the machine be rebuilt in the field. Often when engines are rebuilt the quality of the rebuild may be jeopardized due to incorrect inspection or assembly of major components such as pistons and piston rings. Loss of quality may increase with engines which are rebuilt in the field under less than an ideal controlled environment.
Additionally the amount of time required to prepare components such as piston assemblies for the rebuild process may be significantly greater in a repair shop or the field than if the same work is done in a factory where larger quantities of components are assembled and manufacturing processes and procedures can be systematically followed. Often in the factory, repetitive work is performed at lower labor cost than where the same work is performed by a skilled mechanic in the field.
The present invention overcomes many of the above identified problems by providing piston assemblies which have been inspected and assembled in a factory environment and packaged in a manner which reduces the likelihood of quality related problems. Labor cost to assemble an engine may also be reduced by eliminating the number of steps to assemble the engines.
In one aspect of the invention a piston assembly has a prepackaged configuration and is adapted for use with an engine. The engine is comprised of a piston member with a plurality of ring grooves. A plurality of rings are positioned in the ring grooves. A sleeve is positioned about the piston member and the plurality of rings, maintaining the plurality of rings in a compressed position. A container is positioned about the piston member, plurality of rings, and the sleeve.
In another aspect of the invention a method of assembling a piston assembly in an engine is disclosed. The piston assembly has a prepackaged configuration and comprises a piston member with a plurality of rings thereon and a sleeve positioned around the piston assembly and the plurality of rings. The sleeve maintains the plurality of rings in a compressed position. The method of assembly comprises the following steps. Removing the piston assembly from a container. Positioning the piston assembly in alignment with a cylinder bore. Removing the piston assembly from the sleeve. And, simultaneously inserting the piston assembly into the cylinder bore. The sleeve is discarded after the piston assembly has been installed into the engine.
In another aspect of the invention a sleeve adapted for use with a piston assembly of an engine is provided. The sleeve includes a top surface, a bottom surface and an outer wall. A window is provided in the outer wall.
In another aspect of the invention a method is provided for manufacturing a sleeve for use with a piston assembly having a pre-packaged configuration is provided. The method includes the steps of providing a tube having a predetermined inside diameter, removing a length of the tube and providing a window in the removed tube.